Even a short excursion to 205 degrees isn't a reason to freak out. Maybe try a different thermostat, but once it's open it's on the radiator to keep things cool. In other words, putting a lower temperature thermostat won't make it run cooler if the radiator isn't up to snuff, it won't run at that lower temperature. A higher capacity fan (such as the one that bolts onto the water pump) should help. Most electric fans are too weak, no matter what the claims are.
And Evans coolant (100% propylene glycol) can't work as well as 50% ethylene glycol. 100% water is even more efficient at transferring heat, but has freeze issues. It's a heat capacity thing. Boiling points are higher with 50% EG and Evans, but that isn't usually an issue.
